President Gloria Macapagal Arroyo has formally declared martial law and suspended the writ of habeas corpus in Maguindanao, said Executive Secretary Eduardo Ermita early Saturday.

Ermita and other top officials said martial law and the suspension of the writ of habeas corpus would help government propel the arrest and prosecution of suspects in the Maguindanao massacre.

Proclamation 1959, said Ermita, does not cover areas of Maguindanao where the Moro Islamic Liberation Front holds sway. Manila resume formal peace talks with the MILF next week.

During the same briefing, military chief Victor Ibrado announced that government has taken custody of two more members of the Ampatuan clan said to be behind the massacre of 57 civilians last November 23, 2009. They are Maguindanao Governor Andal Ampatuan Sr. and Autonomous Region of Muslim Mindanao Governor Zaldy Ampatuan.

Andal Ampatuan Jr. was placed in custody last week and has been charged more than two dozen counts of murder in connection with the massacre.

Press Secretary Cerge Remonde last night denied an earlier ABS-CBN news report about the martial law proclamation in Maguindanao which, it turns out, was true.

As part of protections laid down in the Constitution, Congress has to convene within 24 hours upon the declaration of martial law to either approve or invalidate it, while the President is required to make a report within 48 hours. Any citizen may question the declaration before the Supreme Court.

Days prior to President Arroyo’s signing of Proclamation 1959, top officials have rejected suggestions that martial law be declared in response to the Maguindanao massacre.

Congress now has to assess whether the President needs martial law to rein in on the Ampatuans. Arroyo meanwhile has to explain to Congress why she signed Proclamation 1959. The initial slow pace of the Arroyo government’s response to the November 23 massacre drew rebukes from the nation and the world, and allowed the Ampatuans to evade immediate arrest.